Increase in the use of stents, leads, and ablation techniques in branch vessels has provided an increased demand in the placement techniques for the devices. For some procedures, it is necessary to initially position a guidewire into a desired part of the lumen of a desired vessel or duct, such as a blood vessel. After the guidewire is positioned within the desired location, a catheter or other tubular device may be positioned over the guidewire and used to convey other medical instruments into the desired blood vessel or duct.
Alternatively, a guiding catheter is used to negotiate the vasculature of a patient. One example of a guiding catheter is described in U.S. Pat. No. 4,898,577 to Badger et al. The Badger guiding catheter includes a single elongate shaft that has a deflectable distal portion controllable by a pull wire. Once the distal portion is at the required deflection or location within the patient, the medical instrument is fed through the catheter.
The deflectable catheter is controlled at a proximal end of the catheter by a control handle that operates the pull wire to deflect the catheter, for example, as shown in U.S. Pat. No. 6,171,277. However, with conventional catheter steering mechanisms, it is sometimes difficult to accurately position the catheters in certain body vessels, such as branch veins. For instance, the mechanisms are awkward or require the use of two hands. Other steering mechanisms require pull wires to be wound and unwound around a rotatable cam wheel, causing increased fatigue on the pull wires, and potentially shortening the life of the device. Furthermore, some deflectable catheters involve relatively large catheter sheaths. The larger sheaths can be difficult to manipulate within a patient, particularly when using a relatively small wheel mechanism or the above-discussed handle assemblies.
What is needed is a deflectable catheter that overcomes the shortcomings of previous deflectable catheters. What is further needed is a deflectable catheter that allows for more ease positioning of the distal end of the deflectable catheter, and that is usable with a single hand.